Printed circuit board with good performance on impedance

ABSTRACT

A printed circuit board, comprises an insulative substrate, a grounding layer located on a surface of the insulative substrate and defining a through slot, a plurality of conductive pins located on an outer surface of the printed circuit board; and a fence layer located between the conductive path and the grounding layer. Each conductive pin defines at least a soldering portion. The soldering portion is alignment to the through slot along a vertical direction.

FIELD OF THE INVENTION

The present invention relates to a printed circuit board, and moreparticularly to a printed circuit board assembled in an electricalconnector.

DESCRIPTION OF PRIOR ART

For improving the signal transmission rate of an electrical connectorand extensively applying the high-frequency circuits, the requirement ofa printed circuit board assembled in the electrical connector is betterand better. The circuit performance which is provided by the printedcircuit board must be able to make the signal transmission not occur inthe phenomenon of reflection, to maintain signal integrity, to reducetransmission loss and to play a role of matching the impedance. Thus,the transmission signal is complete, reliable, accurate,non-interference and noise-free. The printed circuit board which is usedin the high-frequency electrical connector generally has severalmaterial layers together. The traditional printed circuit board includesan insulative substrate, a grounding layer, a fence layer, and aconductive path made of copper material and located on the outermostthereof. The characteristic impedance of the printed circuit board isdetermined under the conditions of the width of the conductive path, thethickness of the copper material, the thickness and the dielectriccoefficient of the insulative substrate, etc. However, the conductivepath is soldered on a terminal of the electrical connector to form alarge solder joint and broaden the width of the conductive path, so thatthe characteristic impedance becomes smaller and the electricalconnector having the printed circuit board can not achieve thecorresponding association requirement.

As discussed above, an improved printed circuit board overcoming theshortages of existing technology is needed.

SUMMARY OF THE INVENTION

Accordingly, an object of the present invention is to provide a printedcircuit board with good performance on impedance.

In order to achieve the above-mentioned objects, a printed circuitboard, comprises an insulative substrate, a grounding layer located on asurface of the insulative substrate and defining a through slot, aplurality of conductive pins located on an outer surface of the printedcircuit board, and a fence layer located between the conductive path andthe grounding layer. Each conductive pin defines at least a solderingportion. The soldering portion is alignment to the through slot along avertical direction.

Other objects, features and advantages of the invention will be apparentfrom the following detailed description taken in connection with theaccompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a printed circuit board in accordancewith the present invention;

FIG. 2 is a explored, perspective view of the printed circuit boardshown in FIG. 1; and

FIG. 3 is a partly assembled, perspective view of the printed circuitboard shown in FIG. 2.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Reference will now be made to the drawing figures to describe thepresent invention in detail.

Referring to FIGS. 1 to 3, a printed circuit board 100 in accordancewith the present invention comprises an insulative substrate 1, a firstgrounding layer 21 located on a surface of the insulative substrate 1, asecond grounding layer 22 located on another surface of the insulativesubstrate 1, a first fence layer 31 located on a surface of the firstgrounding layer 21, a second fence layer 32 located on another surfaceof the second grounding layer 22, a first conductive path 41 located ona surface of the first fence layer 31 and a second conductive path 42located on another surface of the second fence layer 32.

The first grounding layer 21 comprises a first through slot 211 locatedon the front thereof and a second through slot 212 located on the rearthereof. The second grounding layer 22 comprises a first through slot221 located on the front thereof and a second through slot 222 locatedon the rear thereof. The first fence layer 31 is located between thefirst grounding layer 21 and the first conducts path 41. The secondfence layer 32 is located between the second grounding layer 22 and thesecond conducts path 42. The first conductive path 41 and the secondconductive path 42 respectively located on the upper surface and thelower surface of the printed circuit board 100. The grounding layer 21,22 are made of copper material which is printed on the insulativesubstrate 1.

The first conductive path 41 has a plurality of first conductive pins411. The first conductive pin 411 comprises a first soldering portion4111 located on the front thereof and a second soldering portion 4112located on the rear thereof. The first soldering portions 4111 arearranged in a row along a horizontal direction, and the second solderingportions 4112 are arranged in a row along the horizontal direction. Thesecond conductive path 42 has a plurality of second conductive pins 421.The second conductive pin 421 comprises a first soldering portion 4211located on the front thereof and a second soldering portion 4212 locatedon the rear thereof. The first soldering portions 4211 are arranged in arow along the horizontal direction, and the second soldering portions4212 are arranged in a row along the horizontal direction.

Referring to the FIG. 3, the first soldering portion 4111 and the secondsoldering portion 4112 of the first conductive pin 41 are alignment tothe first through slot 211 and the second through slot 212 of the firstgrounding layer 21 along a vertical direction, respectively. The firstsoldering portion 4211 and the second soldering portion 4212 of thesecond conductive pin 42 are alignment to the first through slot 221 andthe second through slot 222 of the second grounding layer 22 along thevertical direction, respectively. Under the method, it can reduce thecapacitance between the grounding layer and the conductive path forimproving the impedances of the printed circuit board 100 and acorrespondence connector.

The first conductive path 41 and the second conductive path 42 arerespectively made of copper or other metal material which is printed onthe first fence layer 31 and the second fence layer 32. The firstthrough slots 211, 221 and the second through slots 212, 222 are ofrectangular or other shapes, and have a plurality of tiny through slots.

It will be understood that the invention may be embodied in otherspecific forms without departing from the spirit or centralcharacteristics thereof. The present examples and embodiments,therefore, are to be considered in all respects as illustrative and notrestrictive, and the invention is not to be limited to the details givenherein.

1. A printed circuit board, comprising: an insulative substrate; agrounding layer located on a surface of the insulative substrate anddefining a through slot; a plurality of conductive pins located on anouter surface of the printed circuit board, and each conductive pindefining at least a soldering portion; and a fence layer located betweenthe conductive path and the grounding layer; wherein the solderingportion is alignment to the through slot along a vertical direction. 2.The printed circuit board as recited in claim 1, wherein the conductivepin comprises a plurality of first conductive pins which together form afirst conductive path and a plurality of second conductive pins whichtogether form a second conductive path.
 3. The printed circuit board asrecited in claim 2, wherein the first conductive pin and the secondconductive pin respective defines a row of first soldering portionslocated on the front end thereof and a row of second soldering portionslocated on the rear end thereof.
 4. The printed circuit board as recitedin claim 3, wherein the grounding layer comprises a first groundinglayer and a second grounding layer located on an upper surface and alower surface of the insulative substrate.
 5. The printed circuit boardas recited in claim 4, wherein the first grounding layer defines a firstthrough slot alignment to a row of the first soldering portion of thefirst conductive pin along the vertical direction and a second throughslot alignment to a row of the second soldering portion of the firstconductive pin along the vertical direction.
 6. The printed circuitboard as recited in claim 5, wherein the first through slot is locatedon the front end of the first grounding layer, and the second throughslot is located on the front end of the second grounding layer.
 7. Theprinted circuit board as recited in claim 4, wherein the secondgrounding layer defines a first through slot alignment to a row of thefirst soldering portion of the second conductive pin along the verticaldirection and a second through slot alignment to a row of the secondsoldering portion of the second conductive pin along the verticaldirection.
 8. The printed circuit board as recited in claim 7, whereinthe first through slot is located on the front end of the second layer,and the second through slot is located on the rear end of the secondlayer.
 9. The printed circuit board as recited in claim 4, wherein thefence layer comprises a first fence layer between the first conductivepath and the first grounding layer, and a second fence layer between thesecond conductive path and the second grounding layer.
 10. The printedcircuit board as recited in claim 1, wherein the through slot is ofrectangular.
 11. The printed circuit board as recited in claim 1,wherein the conductive pin is made of copper material which is printedon the fence layer.
 12. The printed circuit board as recited in claim 1,wherein the grounding layer is made of copper material which is printedon the insulative substrate.
 13. A printed circuit board comprising: aninsulative substrate; a grounding layer coated upon the substrate anddefining some empty areas; a plurality of conductive traces formed uponan exterior surface of the printed circuit board and definingcorresponding soldering portions thereof, respectively; and a fencelayer disposed between the grounding layer and the conductive traces ina vertical direction perpendicular to said printed circuit board;wherein the empty areas are essentially aligned with the correspondingsoldering portions in the vertical direction, respectively.
 14. Theprinted circuit board as claimed in claim 13, wherein said empty areasare unified together to form a through slot along a transverse directionperpendicular to said vertical direction.
 15. The printed circuit boardas claimed in claim 13, wherein each of said conductive traces definestwo opposite soldering portions in a front-to-back directionperpendicular to said vertical direction.
 16. The printed circuit boardas claimed in claim 15, wherein said empty areas are unified together toform two through slots along a transverse direction perpendicular tosaid vertical direction and said transverse direction.
 17. The printedcircuit board as claimed in claim 15, wherein said conductive tracesform first and second rows of soldering portions in a transversedirection perpendicular to both said vertical direction and saidtransverse direction, and the soldering portions in the first row spanin a region larger than those in the second row in the transversedirection and the printed circuit board defines two opposite end regionsunder condition that one end region corresponding to the solderingportions in the first row, is dimensioned, along the transversedirection, larger than those corresponding to the soldering portions inthe second row.